Apparatus and method for generating identification key

Abstract

Provided is a PUF by which an identification key is generated according to a random event caused by a semiconductor process variation. The PUF can provide the identification key as a result of electrical differences among elements. According to one embodiment, the PUF can accumulate the electrical differences and/or instantaneous values without generating the identification key by using the instantaneous values caused by the electrical differences. The accumulation may be the accumulation of a discrete iteration and the result thereof. However, according to another embodiment, the accumulation may be a continuation of the accumulation result during time intervals.

The invention claimed is: 
     
       1. An apparatus for generating an identification key, the apparatus comprising:
 a generator configured to provide a random event based on a semiconductor process variation, the random event being associated with an electrical property difference; 
 an accumulator configured to perform an accumulation on the random event to provide a cumulative result value; and 
 a reader configured to determine the cumulative result value to be a binary value corresponding to one of 0 and 1 based on a predetermined reference and provide an the identification key corresponding to the generator, 
 wherein the random event includes an event that, between two identically designed and manufactured elements, a first element has a greater electrical property value than that of a second element, and 
 wherein each of the first element and the second element includes a resistor and the electrical property value includes a resistance value, 
 wherein the accumulator comprises: 
 an integrator configured to perform a current integration by accumulating, into an output, a current proportional to a difference between a first resistance value corresponding to the first element and a second resistance value corresponding to the second element until a predetermined condition is satisfied, and provide a value of the output in a case in which the predetermined condition is satisfied. 
 
     
     
       2. The apparatus of  claim 1 , wherein the predetermined condition includes the value of the output being greater than or equal to a threshold. 
     
     
       3. The apparatus of  claim 1 , wherein the predetermined condition includes the current integration being performed for a predetermined period of time. 
     
     
       4. An apparatus for generating an identification key, the apparatus comprising:
 a generator including a first element having an electrical property value differing from electrical property values of elements designed identically to the first element, based on a semiconductor process variation, wherein an electrical value is output based on whether the electrical property value is greater than a reference value; 
 an accumulator configured to perform an accumulation on the electrical value and provide a cumulative result value; and 
 a reader configured to provide the identification key corresponding to the generator based on the cumulative result value, 
 wherein the electrical property value includes a resistance value, 
 wherein the accumulator comprises: 
 an integrator configured to perform a voltage distribution of a power source voltage based on a ratio between a first resistance value corresponding to the first element and the reference value, perform a current integration by accumulating, into an output, a current proportional to a difference between the first resistance value and the reference value until a predetermined condition is satisfied, and provide a value of the output in a case in which the predetermined condition is satisfied. 
 
     
     
       5. The apparatus of  claim 4 , wherein the predetermined condition includes the current integration being performed for a predetermined period of time. 
     
     
       6. A method of operating an identification key generating apparatus, the method comprising:
 generating, by a generator, a random event based on a semiconductor process variation; 
 accumulating a result of the random event using a predetermined scheme and providing a cumulative result value obtained by accumulating a result value of the random event; and 
 reading an identification key corresponding to the identification key generating apparatus using the cumulative result value, 
 wherein the random event includes an event that, between two identically designed and manufactured elements, a first element has a greater electrical property value than that of a second element, and 
 wherein each of the first element and the second element includes a resistor and the electrical property value includes a resistance value, 
 wherein the accumulating is performed by using performing a current integration by:
 accumulating, into an output, a current proportional to a difference between a first resistance value corresponding to the first element and a second resistance value corresponding to the second element until a predetermined condition is satisfied, and 
 
 providing a value of the output in a case in which the predetermined condition is satisfied.